Preheat the oven to 180 degrees Celsius (350 degrees Fahrenheit).

Heat vegetable oil in a skillet over medium heat.

Add minced onion, leek, and diced carrot to the skillet.

Sauté the vegetables for 5 minutes until softened.

Add minced meat to the skillet.

Season with salt and black pepper.

Cook the meat for 5 minutes, breaking it up with a spoon.

Remove from heat and let the mixture cool slightly.

Place a wonton wrapper on a cutting board.

Spoon some of the meat and vegetable filling into the center of the wrapper.

Add some shredded cheddar cheese on top of the filling.

Roll the wrapper partially, pressing the filling together.

Fold in the sides of the wrapper.

Continue rolling to create a spring roll shape.

Brush the edge of the wrapper with beaten egg to seal it.

Repeat the process with the remaining wrappers and filling.

Place the spring rolls on a baking sheet.

Bake for 15 minutes, or until golden brown and crispy.

Alternatively, fry the spring rolls in hot oil until golden brown.